<!-- Licensed under a BSD license. See license.html for license -->
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
    <title>Three.js - Lots of Objects - Morphtargets</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
        color: white;
    }
    #c {
        width: 100%;
        height: 100%;
        display: block;
    }
    #ui {
      position: absolute;
      left: 1em;
      top: 1em;
    }
    #ui>div {
      font-size: 20pt;
      padding: 1em;
      display: inline-block;
    }
    #ui>div.selected {
      color: red;
    }
    @media (max-width: 700px) {
      #ui>div {
        display: block;
        padding: .25em;
      }
    }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
    <div id="ui"></div>
  </body>
<!-- Import maps polyfill -->
<!-- Remove this when import maps will be widely supported -->
<script async src="https://unpkg.com/es-module-shims@1.3.6/dist/es-module-shims.js"></script>

<script type="importmap">
{
  "imports": {
    "three": "../../build/three.module.js",
    "three/addons/": "../../examples/jsm/"
  }
}
</script>

<script type="module">
import * as THREE from 'three';
import * as BufferGeometryUtils from 'three/addons/utils/BufferGeometryUtils.js';
import {OrbitControls} from 'three/addons/controls/OrbitControls.js';
import {TWEEN} from 'three/addons/libs/tween.module.min.js';

class TweenManger {
  constructor() {
    this.numTweensRunning = 0;
  }
  _handleComplete() {
    --this.numTweensRunning;
    console.assert(this.numTweensRunning >= 0);  /* eslint no-console: off */
  }
  createTween(targetObject) {
    const self = this;
    ++this.numTweensRunning;
    let userCompleteFn = () => {};
    // create a new tween and install our own onComplete callback
    const tween = new TWEEN.Tween(targetObject).onComplete(function(...args) {
      self._handleComplete();
      userCompleteFn.call(this, ...args);
    });
    // replace the tween's onComplete function with our own
    // so we can call the user's callback if they supply one.
    tween.onComplete = (fn) => {
      userCompleteFn = fn;
      return tween;
    };
    return tween;
  }
  update() {
    TWEEN.update();
    return this.numTweensRunning > 0;
  }
}

function main() {
  const canvas = document.querySelector('#c');
  const renderer = new THREE.WebGLRenderer({canvas});
  const tweenManager = new TweenManger();

  const fov = 60;
  const aspect = 2;  // the canvas default
  const near = 0.1;
  const far = 10;
  const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  camera.position.z = 2.5;

  const controls = new OrbitControls(camera, canvas);
  controls.enableDamping = true;
  controls.enablePan = false;
  controls.minDistance = 1.2;
  controls.maxDistance = 4;
  controls.update();

  const scene = new THREE.Scene();
  scene.background = new THREE.Color('black');

  {
    const loader = new THREE.TextureLoader();
    const texture = loader.load('resources/images/world.jpg', render);
    const geometry = new THREE.SphereGeometry(1, 64, 32);
    const material = new THREE.MeshBasicMaterial({map: texture});
    scene.add(new THREE.Mesh(geometry, material));
  }

  async function loadFile(url) {
    const req = await fetch(url);
    return req.text();
  }

  function parseData(text) {
    const data = [];
    const settings = {data};
    let max;
    let min;
    // split into lines
    text.split('\n').forEach((line) => {
      // split the line by whitespace
      const parts = line.trim().split(/\s+/);
      if (parts.length === 2) {
        // only 2 parts, must be a key/value pair
        settings[parts[0]] = parseFloat(parts[1]);
      } else if (parts.length > 2) {
        // more than 2 parts, must be data
        const values = parts.map((v) => {
          const value = parseFloat(v);
          if (value === settings.NODATA_value) {
            return undefined;
          }
          max = Math.max(max === undefined ? value : max, value);
          min = Math.min(min === undefined ? value : min, value);
          return value;
        });
        data.push(values);
      }
    });
    return Object.assign(settings, {min, max});
  }

  function dataMissingInAnySet(fileInfos, latNdx, lonNdx) {
    for (const fileInfo of fileInfos) {
      if (fileInfo.file.data[latNdx][lonNdx] === undefined) {
        return true;
      }
    }
    return false;
  }

  function makeBoxes(file, hueRange, fileInfos) {
    const {min, max, data} = file;
    const range = max - min;

    // these helpers will make it easy to position the boxes
    // We can rotate the lon helper on its Y axis to the longitude
    const lonHelper = new THREE.Object3D();
    scene.add(lonHelper);
    // We rotate the latHelper on its X axis to the latitude
    const latHelper = new THREE.Object3D();
    lonHelper.add(latHelper);
    // The position helper moves the object to the edge of the sphere
    const positionHelper = new THREE.Object3D();
    positionHelper.position.z = 1;
    latHelper.add(positionHelper);
    // Used to move the center of the cube so it scales from the position Z axis
    const originHelper = new THREE.Object3D();
    originHelper.position.z = 0.5;
    positionHelper.add(originHelper);

    const color = new THREE.Color();

    const lonFudge = Math.PI * .5;
    const latFudge = Math.PI * -0.135;
    const geometries = [];
    data.forEach((row, latNdx) => {
      row.forEach((value, lonNdx) => {
        if (dataMissingInAnySet(fileInfos, latNdx, lonNdx)) {
          return;
        }
        const amount = (value - min) / range;

        const boxWidth = 1;
        const boxHeight = 1;
        const boxDepth = 1;
        const geometry = new THREE.BoxGeometry(boxWidth, boxHeight, boxDepth);

        // adjust the helpers to point to the latitude and longitude
        lonHelper.rotation.y = THREE.MathUtils.degToRad(lonNdx + file.xllcorner) + lonFudge;
        latHelper.rotation.x = THREE.MathUtils.degToRad(latNdx + file.yllcorner) + latFudge;

        // use the world matrix of the origin helper to
        // position this geometry
        positionHelper.scale.set(0.005, 0.005, THREE.MathUtils.lerp(0.01, 0.5, amount));
        originHelper.updateWorldMatrix(true, false);
        geometry.applyMatrix4(originHelper.matrixWorld);

        // compute a color
        const hue = THREE.MathUtils.lerp(...hueRange, amount);
        const saturation = 1;
        const lightness = THREE.MathUtils.lerp(0.4, 1.0, amount);
        color.setHSL(hue, saturation, lightness);
        // get the colors as an array of values from 0 to 255
        const rgb = color.toArray().map(v => v * 255);

        // make an array to store colors for each vertex
        const numVerts = geometry.getAttribute('position').count;
        const itemSize = 3;  // r, g, b
        const colors = new Uint8Array(itemSize * numVerts);

        // copy the color into the colors array for each vertex
        colors.forEach((v, ndx) => {
          colors[ndx] = rgb[ndx % 3];
        });

        const normalized = true;
        const colorAttrib = new THREE.BufferAttribute(colors, itemSize, normalized);
        geometry.setAttribute('color', colorAttrib);

        geometries.push(geometry);
      });
    });

    return BufferGeometryUtils.mergeBufferGeometries(
       geometries, false);
  }

  async function loadData(info) {
    const text = await loadFile(info.url);
    info.file = parseData(text);
  }

  async function loadAll() {
    const fileInfos = [
      {name: 'men',   hueRange: [0.7, 0.3], url: 'resources/data/gpw/gpw_v4_basic_demographic_characteristics_rev10_a000_014mt_2010_cntm_1_deg.asc' },
      {name: 'women', hueRange: [0.9, 1.1], url: 'resources/data/gpw/gpw_v4_basic_demographic_characteristics_rev10_a000_014ft_2010_cntm_1_deg.asc' },
    ];

    await Promise.all(fileInfos.map(loadData));

    function mapValues(data, fn) {
      return data.map((row, rowNdx) => {
        return row.map((value, colNdx) => {
          return fn(value, rowNdx, colNdx);
        });
      });
    }

    function makeDiffFile(baseFile, otherFile, compareFn) {
      let min;
      let max;
      const baseData = baseFile.data;
      const otherData = otherFile.data;
      const data = mapValues(baseData, (base, rowNdx, colNdx) => {
        const other = otherData[rowNdx][colNdx];
          if (base === undefined || other === undefined) {
            return undefined;
          }
          const value = compareFn(base, other);
          min = Math.min(min === undefined ? value : min, value);
          max = Math.max(max === undefined ? value : max, value);
          return value;
      });
      // make a copy of baseFile and replace min, max, and data
      // with the new data
      return {...baseFile, min, max, data};
    }

    // generate a new set of data
    {
      const menInfo = fileInfos[0];
      const womenInfo = fileInfos[1];
      const menFile = menInfo.file;
      const womenFile = womenInfo.file;

      function amountGreaterThan(a, b) {
        return Math.max(a - b, 0);
      }
      fileInfos.push({
        name: '>50%men',
        hueRange: [0.6, 1.1],
        file: makeDiffFile(menFile, womenFile, (men, women) => {
          return amountGreaterThan(men, women);
        }),
      });
      fileInfos.push({
        name: '>50% women',
        hueRange: [0.0, 0.4],
        file: makeDiffFile(womenFile, menFile, (women, men) => {
          return amountGreaterThan(women, men);
        }),
      });
    }

    // make geometry for each data set
    const geometries = fileInfos.map((info) => {
      return makeBoxes(info.file, info.hueRange, fileInfos);
    });

    // use the first geometry as the base
    // and add all the geometries as morphtargets
    const baseGeometry = geometries[0];
    baseGeometry.morphAttributes.position = geometries.map((geometry, ndx) => {
      const attribute = geometry.getAttribute('position');
      const name = `target${ndx}`;
      attribute.name = name;
      return attribute;
    });
    baseGeometry.morphAttributes.color = geometries.map((geometry, ndx) => {
      const attribute = geometry.getAttribute('color');
      const name = `target${ndx}`;
      attribute.name = name;
      return attribute;
    });
    const material = new THREE.MeshBasicMaterial({
      vertexColors: true,
    });
    const mesh = new THREE.Mesh(baseGeometry, material);
    scene.add(mesh);

    // show the selected data, hide the rest
    function showFileInfo(fileInfos, fileInfo) {
      const targets = {};
      fileInfos.forEach((info, i) => {
        const visible = fileInfo === info;
        info.elem.className = visible ? 'selected' : '';
        targets[i] = visible ? 1 : 0;
      });
      const durationInMs = 1000;
      tweenManager.createTween(mesh.morphTargetInfluences)
        .to(targets, durationInMs)
        .start();
      requestRenderIfNotRequested();
    }

    const uiElem = document.querySelector('#ui');
    fileInfos.forEach((info) => {
      const div = document.createElement('div');
      info.elem = div;
      div.textContent = info.name;
      uiElem.appendChild(div);
      function show() {
        showFileInfo(fileInfos, info);
      }
      div.addEventListener('mouseover', show);
      div.addEventListener('touchstart', show);
    });
    // show the first set of data
    showFileInfo(fileInfos, fileInfos[0]);
  }
  loadAll();

  function resizeRendererToDisplaySize(renderer) {
    const canvas = renderer.domElement;
    const width = canvas.clientWidth;
    const height = canvas.clientHeight;
    const needResize = canvas.width !== width || canvas.height !== height;
    if (needResize) {
      renderer.setSize(width, height, false);
    }
    return needResize;
  }

  let renderRequested = false;

  function render() {
    renderRequested = undefined;

    if (resizeRendererToDisplaySize(renderer)) {
      const canvas = renderer.domElement;
      camera.aspect = canvas.clientWidth / canvas.clientHeight;
      camera.updateProjectionMatrix();
    }

    if (tweenManager.update()) {
      requestRenderIfNotRequested();
    }

    controls.update();
    renderer.render(scene, camera);
  }
  render();

  function requestRenderIfNotRequested() {
    if (!renderRequested) {
      renderRequested = true;
      requestAnimationFrame(render);
    }
  }

  controls.addEventListener('change', requestRenderIfNotRequested);
  window.addEventListener('resize', requestRenderIfNotRequested);
}

main();
</script>
</html>

